3.5. Pre-Partitioning for Multi-Boot Systems

Partitioning your disk simply refers to the act of breaking up your
disk into sections. Each section is then independent of the others.
It's roughly equivalent to putting up walls inside a house; if you add
furniture to one room it doesn't affect any other room.

If you already have an operating system on your system
(Amiga OS, Atari TOS, Mac OS, …)
and want to stick Linux on the same disk, you will need to repartition
the disk. Debian requires its own hard disk partitions. It cannot be
installed on Windows or MacOS partitions. It may be able to share some
partitions with other Linux systems, but that's not covered here. At
the very least you will need a dedicated partition for the Debian
root.

You can find information about your current partition setup by using
a partitioning tool for your current operating system, such as HD SC Setup, HDToolBox, or SCSITool. Partitioning tools always
provide a way to show existing partitions without making changes.

In general, changing a partition with a file system already on
it will destroy any information there. Thus you should always make
backups before doing any repartitioning. Using the analogy of the
house, you would probably want to move all the furniture out of the
way before moving a wall or you risk destroying it.

If your computer has more than one hard disk, you may want to dedicate
one of the hard disks completely to Debian. If so, you don't need to
partition that disk before booting the installation system; the
installer's included partitioning program can handle the job nicely.

If your machine has only one hard disk, and you would like to
completely replace the current operating system with Debian GNU/Linux,
you also can wait to partition as part of the installation process
(Section 6.3.2.1, “Partitioning Your Disks”), after you have booted the
installation system. However this only works if you plan to boot the
installer system from tapes, CD-ROM or files on a connected machine.
Consider: if you boot from files placed on the hard disk, and then
partition that same hard disk within the installation system, thus
erasing the boot files, you'd better hope the installation is
successful the first time around. At the least in this case, you
should have some alternate means of reviving your machine like the
original system's installation tapes or CDs.

If your machine already has multiple partitions, and enough space can
be provided by deleting and replacing one or more of them, then you
too can wait and use the Debian installer's partitioning program. You
should still read through the material below, because there may be
special circumstances like the order of the existing partitions within
the partition map, that force you to partition before installing
anyway.

If none of the above apply, you'll need to partition your hard disk before
starting the installation to create partition-able space for
Debian. If some of the partitions will be owned by other operating
systems, you should create those partitions using native operating
system partitioning programs. We recommend that you do
not attempt to create partitions for Debian GNU/Linux
using another operating system's tools. Instead, you should just
create the native operating system's partitions you will want to
retain.

If you are going to install more than one operating system on the same
machine, you should install all other system(s) before proceeding with
Linux installation. Windows and other OS installations may destroy
your ability to start Linux, or encourage you to reformat non-native
partitions.

You can recover from these actions or avoid them, but installing
the native system first saves you trouble.

If you currently have one hard disk with one partition (a common setup
for desktop computers), and you want to multi-boot the native
operating system and Debian, you will need to:

Back up everything on the computer.

Boot from the native operating system installer media such as CD-ROM
or tapes.

Use the native partitioning tools to create native system
partition(s). Leave either a place holder partition or free space for
Debian GNU/Linux.

Install the native operating system on its new partition.

Boot back into the native system to verify everything's OK,
and to download the Debian installer boot files.

Boot the Debian installer to continue installing Debian.

3.5.1. Partitioning in AmigaOS

If you are running AmigaOS, you can use the HDToolBox
program to adjust your native partitions prior to installation.

3.5.2. Partitioning in Atari TOS

Atari partition IDs are three ASCII characters, use “LNX” for
data and “SWP” for swap partitions. If using the low memory
installation method, a small Minix partition is also needed (about 2 MB),
for which the partition ID is “MNX”. Failure to set the
appropriate partition IDs not only prevents the Debian installation process
from recognizing the partitions, but also results in TOS attempting to use
the Linux partitions, which confuses the hard disk driver and renders the
whole disk inaccessible.

There are a multitude of third party partitioning tools available (the
Atari harddisk utility doesn't permit changing the
partition ID); this manual cannot give detailed descriptions for all
of them. The following description covers SCSITool (from
Hard+Soft GmBH).

From the Partition menu, select either
New to add new partitions or change the
existing partition sizes, or Change to
change one specific partition. Unless you have already created
partitions with the right sizes and only want to change the partition
ID, New is probably the best choice.

For the New choice, select
existing in the dialog box
prompting the initial settings. The next window shows a list of
existing partitions which you can adjust using the scroll buttons, or
by clicking in the bar graphs. The first column in the partition list
is the partition type; just click on the text field to edit it. When
you are finished changing partition settings, save the changes by
leaving the window with the OK button.

For the Change option, select the partition
to change in the selection list, and select other
systems in the dialog box. The
next window lists detailed information about the location of this
partition, and lets you change the partition ID. Save changes by
leaving the window with the OK button.

Quit SCSITool using the
Quit item from the File
menu. The computer will reboot to make sure the changed partition
table is used by TOS. If you changed any TOS/GEM partitions, they will
be invalidated and have to be reinitialized (we told you to back up
everything on the disk, didn't we?).

There is a partitioning tool for Linux/m68k called
atari-fdisk in the installation system, but for now we
recommend you partition your disk using a TOS partition editor or some
disk tool. If your partition editor doesn't have an option to edit the
partition type, you can do this crucial step at a later stage (from
the booted temporary install RAMdisk). SCSITool is only
one of the partition editors we know of which supports selection of
arbitrary partition types. There may be others; select the tool that
suits your needs.

3.5.3. Partitioning in MacOS

Partitioning tools for Macintosh tested include pdisk,
HD SC Setup 7.3.5 (Apple), HDT 1.8 (FWB),
SilverLining (LaCie), and DiskTool (Tim
Endres, GPL). Full versions are required for HDT and
SilverLining. The Apple tool requires a patch in order
to recognize third-party disks (a description on how to patch HD
SC Setup using ResEdit can be found at
http://www.euronet.nl/users/ernstoud/patch.html).

For IDE based Macs, you need to use Apple Drive Setup to create
empty space for the Linux partitions, and complete the partitioning under
Linux, or use the MacOS version of pdisk available from the MkLinux FTP
server.